r - 如何从R中的矩阵创建边列表？

Question

该关系表示为矩阵 x像这样:

      A    B    C     D
A     0    2    1     1
B     2    0    1     0
C     1    1    0     1
D     1    0    1     0

这些条目是指它们拥有的连接数。

谁能告诉我如何将其写为边缘列表？

我更愿意把它写成一个边缘列表:

A B
A B
A C
A D
B C

但是这个边列表允许我创建一个网络图吗？

Answer 1

使用 igraph包裹:

x <- matrix(c(0,2,1,1,2,0,1,0,1,1,0,1,1,0,1,0), 4, 4)
rownames(x) <- colnames(x) <- LETTERS[1:4]

library(igraph)
g <- graph.adjacency(x)
get.edgelist(g)

#      [,1] [,2]
#  [1,] "A"  "B" 
#  [2,] "A"  "B" 
#  [3,] "A"  "C" 
#  [4,] "A"  "D" 
#  [5,] "B"  "A" 
#  [6,] "B"  "A" 
#  [7,] "B"  "C" 
#  [8,] "C"  "A" 
#  [9,] "C"  "B" 
# [10,] "C"  "D" 
# [11,] "D"  "A" 
# [12,] "D"  "C"

我还建议您花一些时间阅读 igraph文档位于 http://igraph.sourceforge.net/index.html因为你最近的很多问题都是简单的案例用法。

(作为奖励， plot(g) 将回答您的另一个问题 How to plot relationships in R? )